Device for determining the residual liquid content of solids cakes in centrifuges

Abstract

A device for determining the residual liquid content of solids cakes in a centrifuge basket. The device includes two electrodes protruding through a wall of the basket and into the solids cake; a conductivity or capacitance measuring device ( 13 ) measuring the conductivity of the solids cake between the electrodes; and evaluation and control units contactlessly receiving data from the measuring device to affect the operation of the centrifuge.

1. A device for determining the residual liquid content of solids cakes in a rotating basket of a centrifuge, said device comprising:
 at least two electrodes as sensors, disposed to protrude, spaced apart from each other, through a wall of said rotating basket and into a solids cake which accumulates in said basket during operation; 
 a conductivity or capacitance measuring device ( 13 ) connected to the electrode sensors to measure the conductivity of the solids cake between said sensors and to determine the residual liquid content thereby; and 
 evaluation and control units positioned apart from said basket and configured to contactlessly receive data from said measuring device and, in response thereto, affect the operation of the centrifuge. 
 
   
   
     2. The device as claimed in  claim 1 , wherein the basket comprises a basket shell, containing a screen area, a basket base and an edge, and the electrodes are provided in the edge of the basket. 
   
   
     3. The device as claimed in  claim 1 , wherein the measuring device is provided in the edge of the basket. 
   
   
     4. The device as claimed in  claim 1 , the electrodes are of a material selected from the group consisting of stainless steel, platinum, gold, nickel and copper. 
   
   
     5. The device as claimed in  claim 1 , wherein the measuring device is connected to a telemetry unit ( 14 ), which transmits measuring data contactlessly from the centrifuge basket ( 1 ) to a receiver. 
   
   
     6. The device as claimed in  claim 5 , wherein the basket of the centrifuge is mounted in a centrifuge housing, and the receiver is provided on the inside of the centrifuge housing. 
   
   
     7. The device as claimed in  claim 6 , wherein the receiver is connected to said evaluation and control units for controlling the operation of the centrifuge. 
   
   
     8. The device as claimed in  claim 1 , wherein the measuring device is operated by an external voltage supply, arranged partly outside the centrifuge basket. 
   
   
     9. The device as claimed in  claim 8 , wherein the voltage supply comprises a high-frequency transmitter with a transmitting coil and an AC/DC converter with a receiver coil, the AC/DC converter being electrically connected to the measuring device. 
   
   
     10. The device as claimed in  claim 8 , wherein the voltage supply, the measuring device and a telemetry unit which transmits measuring data contactlessly from the centrifuge basket to a receiver are arranged in a ring, closed from the surroundings, which ring is comprised of a non-metallic material. 
   
   
     11. The device as claimed in  claim 10 , wherein the non-metallic material is a curable plastic. 
   
   
     12. The device as claimed in  claim 11 , wherein said curable plastic is an epoxy resin or a phenolic resin. 
   
   
     13. The device as claimed in  claim 10 , wherein the basket comprises a basket shell, containing a screen area, a basket base and a basket edge, and an additional supporting ring is provided around the outer circumference of the ring and is connected to the basket edge. 
   
   
     14. The device as claimed in  claim 10 , wherein said non-metallic material is a glass-fiber reinforced plastic. 
   
   
     15. A skimming centrifuge, filter centrifuge, centrifugal dryer or screen centrifuge comprising a measuring device according to  claim 1 .